KR20000058133A - Electron-emitting device, electron source and image-forming apparatus, and manufacturing methods thereof - Google Patents

Abstract

PURPOSE: An electron emission device, electron source and image forming device and method for fabricating the same is provided to give a long period reliable and good characteristic of electron emitter. CONSTITUTION: An electron emission device, electron source and image forming device and method for fabricating the same comprising a conductive member having 2nd gap(17) is arranged on a substrate(11); at least the 2nd gap is irradiated with the electron beam from the electron emission device arranged and spaced from the conductive member in a carbon compound contained atmosphere; a power voltage applied on the conductive member in a carbon compound contained atmosphere

Description

ELECTRON-EMITTING DEVICE, ELECTRON SOURCE AND IMAGE-FORMING APPARATUS, AND MANUFACTURING METHODS THEREOF

The present invention relates to an electron emitting device, an electron source using a plurality of electron emitting devices, an image forming apparatus such as a display device, an electron emitting device and an exposure device using an electron source, and the like, and a manufacturing method thereof.

The electron emitting devices known in the art are largely two types of electron emitting devices, a hot cathode type and a cold cathode type. Cold cathodes are further classified into field emission type (hereinafter referred to as "FE type"), metal / insulating layer / metal type (hereinafter referred to as MIM type) and surface conduction type. FE type electron emission devices include "Field emission" by W. P. Dyke and W. W. Dolan, published in Advance in Electron Physics, 8, 89 (1956), and J. Appl. Electron emission devices disclosed in C. A. Spindt, "PHYSICAL Properties of thin-film field emission cathodes with molybdenum cones," published in Phys., 47, 5248 (1976).

As the MIM type electron emission device, J. Appl. Electron emission devices disclosed in C. A. Mead, "Operation of Tunnel-Emission Devices" published in Phys., 32, 646 (1961).

Surface-conductive electron-emitting devices include Recio. Eng. Electron emitting devices disclosed in M. I. Elinson's paper published in Electron Phys., 10, 1290 (1965) and the like are known.

Surface conduction electron-emitting devices make use of a phenomenon in which electrons are emitted by supplying current to a thin and small area film formed on a substrate in parallel with the surface of the film. Reported as a surface conduction electron-emitting device is a device using the SnO2 thin film disclosed in the paper described in Elinson et al., And a device using the Au thin film [G. Dittmer: "Thin Solid Film," 9, 317 (1972), and devices using In2O3 / SnO2 thin films [M. Hartwell and C.G. Fonstad: "IEEE Trans. Ed Conf." 519 (1975), and devices using carbon thin films [Hisashi Araki et al .: shinku (Vacuum), Vol. 26, No. 1, p. 22 (1983).

FIG. 11 schematically shows the configuration of a device disclosed in the paper of M. Hartwell as a representative example of a surface conduction electron emitting device. In Fig. 11, reference numeral 111 denotes a substrate. Reference numeral 114 denotes a conductive film made of a metal oxide thin film formed by sputtering as a H-shaped pattern, and an electron emission region 115 is formed by a current supply process. In Fig. 11, an interval L of 0.5 to 1 mm is secured between the element electrodes and W 'is set to 0.1 mm.

Conventionally, it is common to form the electron emission region 115 on the surface conduction electron emission element by conducting an energization process called " forming " to the conductive film 114 before emitting electrons. Specifically, the conductive film 114 is locally destroyed, deformed, or degraded by applying a DC voltage or a pulse voltage across the conductive film 114 to form an electron emission region 115 having an electrical state of high resistance. . In this step, the conductive film 114 partially cracks and forms a gap.

As described above, the gap-formed surface conduction electron emission device emits electrons from the electron emission region 115 (near the gaps) when a current is supplied to the device by applying a voltage to the conductive film 114.

It is possible to construct an image forming apparatus by forming a plurality of electron emitting elements as described above on the electron source substrate and combining them with an image forming member made of a fluorescent material or the like.

However, the electron emitting device disclosed in the paper of M. Hartwell is not always satisfactory in terms of stable electron emission characteristics and electron emission efficiency, and therefore it is very difficult to provide an image forming apparatus having high brightness and excellent operational stability.

Therefore, a process called an activation process can be performed as disclosed in Japanese Patent Laid-Open Nos. 08-264112, 08-162015, 09-027268, 09-027272, 10-003848, 10-003847, 10-003853, and 10-003854. . The activation treatment process is a process for significantly changing the device current If and the emission current Ie.

Like the forming process, the activation process may be performed by repeating the application of a pulse voltage to the device in an atmosphere containing organic matter. This treatment allows a film of carbon and / or carbon compound, which is deposited from the organic material present in the atmosphere onto at least the electron emission region, which significantly changes the device current If and emission current Ie, and thus better electron emission characteristics. You will get

An example of the conventional manufacturing method of an electron emitting element is demonstrated with reference to FIGS. 19A-19D.

First, the 1st electrode 2 and the 2nd electrode 3 are arrange | positioned on the board | substrate 1 (FIG. 19A).

Next, a conductive film 4 is arranged to connect the first and second electrodes (FIG. 19B).

Next, the forming process is performed. Specifically, a second gap 6 is formed in a portion of the conductive film 4 by flowing a current through the conductive film (FIG. 19C).

In addition, the activation process is performed. Specifically, by applying a voltage to the conductive film, the carbon film 10 is formed on the conductive film 4 in the second gap 6 on the substrate 1 and near the gap 6. This activation process forms a first gap 7 narrower than the second gap, thereby forming an electron emission region 5 (Fig. 19D).

According to an aspect of the present invention, there is provided a method of manufacturing an electron emission device, comprising: disposing a conductive member having a second gap on a substrate; Irradiating an electron beam to at least the second gap in an atmosphere containing a carbon compound from an electron emission means disposed away from the conductive member; And applying a voltage to the conductive member in an atmosphere containing a carbon compound.

In addition, the method of manufacturing an electron emitting device according to the present invention comprises the steps of: disposing a first and a second conductive member on the substrate with a second gap therebetween; Irradiating an electron beam to at least the second gap in an atmosphere containing a carbon compound from an electron emitting means disposed away from the conductive members; And applying a voltage to the first and second conductive members.

In addition, the method of manufacturing an electron emitting device according to the present invention comprises the steps of: disposing a conductive member having a second gap on the substrate; And applying a voltage to the conductive member while irradiating an electron beam to at least the second gap in an atmosphere containing a carbon compound from an electron emitting means disposed away from the conductive member.

In addition, the method of manufacturing an electron emitting device according to the present invention comprises the steps of: disposing a first and a second conductive member on the substrate with a second gap therebetween; And applying a voltage to the first and second conductive members while irradiating the electron beam to at least the second gap in an atmosphere containing a carbon compound from the electron emitting means disposed away from the conductive members.

In addition, the method of manufacturing an electron emitting device according to the present invention comprises the steps of: disposing a conductive member having a second gap on the substrate; And irradiating an electron beam to at least the second gap in an atmosphere containing a carbon compound from an electron emission means disposed away from the conductive member during a period where a voltage is applied to the conductive member.

In addition, the method of manufacturing an electron emitting device according to the present invention comprises the steps of: disposing a first and a second conductive member on the substrate with a second gap therebetween; And irradiating an electron beam to at least the second gap in an atmosphere containing a carbon compound from an electron emission means disposed away from the conductive members during a period in which voltage is applied to the first and second conductive members.

In addition, the manufacturing method according to the present invention described above can be preferably applied to the manufacturing method of the electron source having a plurality of electron emitting devices.

In addition, the manufacturing method according to the present invention described above can be preferably applied to the manufacturing method of the image forming apparatus having the electron source and the image forming member.

The electron-emitting device according to the present invention is characterized in that it is an electron-emitting device having a carbon film having a resistivity of 0.001 Ωm or less.

In addition, the electron emitting device according to the present invention described above can be preferably applied to an electron source having a plurality of electron emitting devices.

Further, the electron emitting device according to the present invention can be preferably applied to an image forming apparatus having an electron source and an image forming member.

1A and 1B are schematic diagrams showing the configuration of a preferred embodiment of an electron emitting device according to the present invention.

2A, 2B, 2C, and 2D are schematic diagrams showing steps of manufacturing the electron emitting device shown in FIGS. 1A and 1B.

3 shows a voltage waveform used to form an electron emission region of an electron emission element according to the present invention.

Fig. 4 is a schematic diagram showing electron irradiation means used in the activation step of the method of manufacturing an electron emitting device according to the present invention.

5 is a schematic diagram showing an evaluation device used to evaluate electron emission characteristics of an electron emission device according to the present invention.

Fig. 6 is a diagram showing a relationship between emission current Ie, element current If, and element voltage Vf in the electron emission element according to the present invention.

7A and 7B show a configuration of a preferred embodiment of the electron source according to the present invention.

8A and 8B show voltage waveforms for the activation step of the electron source shown in FIGS. 7A and 7B.

9A and 9B are schematic diagrams showing the trajectory of the electron beam in the activation step of the electron source shown in Figs. 7A and 7B.

10A and 10B show another example of the voltage waveform used in the activation step of the electron source according to the present invention.

11 is a schematic diagram showing a conventional electron emitting device.

Fig. 12 is a schematic block diagram showing an electron source having a simple matrix structure as an embodiment of the electron source according to the present invention.

Fig. 13 is a schematic block diagram showing a display panel used in an embodiment of an image forming apparatus according to the present invention using an electron source having a simple matrix structure.

14A and 14B show a fluorescent film on the display panel shown in FIG.

FIG. 15 illustrates a driving circuit for driving the display panel shown in FIG. 13. FIG.

Fig. 16 is a schematic diagram showing an electron source having a ladder structure preferred as an embodiment of the electron source according to the present invention.

Fig. 17 is a schematic diagram showing a display panel used in an embodiment of an image forming apparatus according to the present invention using an electron source having a ladder structure.

18 is a block diagram showing an example of an image forming apparatus according to the present invention.

19A, 19B, 19C, and 19D are schematic views showing examples of the method of manufacturing the electron emitting device according to the present invention.

20 is a schematic diagram showing a problem solved by the present invention.

21A and 21B are schematic diagrams showing examples of electron emitting devices according to the present invention.

22A and 22B are schematic views showing an example of a method of manufacturing an electron emitting device according to the present invention.

Fig. 23 is a schematic diagram showing an example of a method of manufacturing an electron emitting device according to the present invention.

24A, 24B and 24C are schematic views showing examples of the manufacturing method according to the present invention.

25D and 25E are schematic views showing examples of the manufacturing method according to the present invention.

26D, 26E and 25F are schematic views showing examples of the manufacturing method according to the present invention.

<Explanation of symbols for the main parts of the drawings>

11: substrate

12, 13: device electrode

14: conductive film

15: carbon film (conductive film)

16: second gap

17: first gap

In order for an image forming apparatus using an electron emitting element to stably display a bright image, it is desired to maintain electron emission characteristics for a longer time more stably with high electron emission efficiency.

Herein, the electron emission efficiency refers to a current emitted in a vacuum with respect to a current supplied between device electrodes (hereinafter referred to as device current If) when a voltage is applied across a pair of device electrodes of an electron emission device facing each other. Current Ie).

When high electron emission efficiency can be stably controlled for a long time, it is possible to obtain an image forming apparatus such as a flat display which uses, for example, a fluorescent material as an image forming member and forms a bright high quality image at low power.

For such applications, the emission current Ie should be sufficient at the utility voltage level (e.g. 10V to 20V), the device current If should not change significantly during operation, and the emission current Ie and device current If will not degrade for a long time. Should not.

However, as mentioned above, the conventional manufacturing method of a surface conduction electron emission element has the following problems.

The characteristics of the device, such as the electron emission efficiency, and the lifetime of the device depend on the structure and stability of the carbon film 10 (see Fig. 19D) composed of carbon and / or carbon compounds deposited in the activation step.

In addition, the shape of the second gap 6 formed in the forming step may have a shape having a uniform width as shown in FIG. 20. 20 is a schematic plan view of the device that has undergone the forming step (FIG. 19C). In addition, the second gap 6 formed in the forming step may be shaped to bend significantly between the electrodes 2 and 3. When the second gap 6 formed in the forming step has a uniform shape as described above, a uniform electric field is formed in the gap 6 by applying a voltage across the device electrodes 2 and 3.

Even when the second gap 6 has a uniform shape, a carbon film made of carbon and / or a carbon compound in the gap 6 on the substrate 1 and on the conductive film 4 in the vicinity of the gap 6 ( By depositing 10) the gap 6 can be covered in the activation step so that the width thereof can be substantially narrowed.

As a result, by the activation step, the change in the width of the gap 6 formed in the forming step can be reduced, and the emission current Ie and the device current If can be improved.

However, the nonuniformity of the distance from the device electrodes 2, 3 to the gap 6 cannot be basically reduced even if the activation step is performed.

In addition, the deposition amount of the carbon film 10 formed in the activation step may be non-uniform depending on the nonuniformity of the width of the gap 6 formed in the forming step.

Because of this nonuniformity, the effective voltage applied to the first gap 7 becomes nonuniform when a voltage is applied to the element electrodes 2, 3. In addition, the emission current Ie may vary depending on the position, or because a locally high electric field is applied, there is a region that is likely to deteriorate.

In addition, conventional fabrication methods that cannot provide the required electron emission efficiency vary the emission current Ie between the elements and allow their properties to change or degrade during operation.

In order to obtain a high precision image forming apparatus applicable to a flat panel display using an electron emitting device, it is necessary to form an electron emitting region of the electron emitting device, a carbon film composed of carbon and / or a carbon compound having a more preferable structure and more preferable stability. There is.

Accordingly, it is necessary to deposit carbon and / or carbon compounds having a more preferable structure and more preferable stability onto the electron emitting device in order to obtain a high precision image forming apparatus applicable to flat televisions using the electron emitting device.

In view of the above-described problems, the present invention exhibits good and long-term good electron emission efficiency uniformly and stably, and constitutes an electron source using the method of manufacturing an electron emitting element and a method of manufacturing an image forming apparatus, and by the manufacturing method, good electron emission A method of manufacturing an electron emitting device capable of exhibiting efficiency and an electron emitting device providing an electron source is achieved, and an image forming apparatus using an electron source and having excellent brightness and uniform display characteristics is provided. In view of the above-described problems, the present invention exhibits good electron emission efficiency for a long time, constitutes an electron source using the method for producing an electron emission element and a method for producing an image forming apparatus, and has an electron emission element and an electron having good uniform electron emission efficiency. A method of manufacturing an electron emitting device that provides a source is realized, and a high brightness image forming apparatus using an electron source and excellent in display characteristics is provided.

From now on, an embodiment of the manufacturing method according to the invention will be described in detail with reference to FIGS. 1A and 1B, 2A to 2D and 4. FIG.

1A and 1B are schematic diagrams showing the configuration of a surface conduction electron emitting device to which the present invention is preferably applied. FIG. 1A is a plan view and FIG. 1B is a cross-sectional view taken along the line 1B-1B in FIG. 1A. 2a to 2d and 4 are schematic diagrams showing a part of the manufacturing method according to the present invention.

1A and 1B, 2A to 2D, and 4, reference numeral 11 is a substrate, reference numerals 12 and 13 are element electrodes, reference numeral 14 is a conductive film, and reference numeral 15 is a carbon main component. The phosphorus carbon film (conductive film), reference numeral 16 denotes the second gap, and reference numeral 17 denote the first gap.

(Step A)

First, electrodes 12 and 13 opposed to each other are formed. To this end, the substrate 11 is sufficiently cleaned using a detergent, pure water, an organic solution, and the like, and the electrodes 12 and 13 are deposited by depositing an electrode material by vacuum deposition, sputtering, or the like, and then using a photolithography technique. It is formed on (11) (FIG. 2A). Alternatively, the electrode can be formed by a printing method such as an offset printing method. It is preferable to use a printing method, in particular an offset printing method, because the electrode is inexpensively formed to have a large area.

Useful as the substrate 11 in the present invention is a glass substrate, a ceramic substrate, or a Si substrate composed of glass with reduced content of impurities such as Na, silica glass, soda lime glass, and soda lime glass coated with SiO 2 by a sputtering process. .

General conductive materials are useful as materials for the electrodes 12 and 13. For example, the material may be a metal such as Ni, Cr, Au, Mo, W, Pt, Ti, Al, Cu or alloys thereof, metals and metal oxides such as Pd, Ag, Au, RuO 2 and Pd-Ag, as described above. Printing conductive materials composed of any metal, alloy and metal oxide and glass, transparent conductive materials such as In 2 O 3 -SnO 2, and conductive materials such as polysilicon.

The space L between the element electrodes, the length W of the element electrode, the conductive film 14 and the like are designed in consideration of the application mode and the like. The space L between the device electrodes is preferably in the range of several hundreds of nm to several hundreds of micrometers, and more preferably in the range of several micrometers to several tens of micrometers in consideration of voltages to be applied across the device electrodes.

In consideration of the resistance value of the electrode and the electron emission efficiency, the length W of the device electrode is preferably in the range of several μm to several hundred μm and the film thickness d of the device electrodes 12 and 13 is preferably in the range of several tens of nm to several μm. Mine

Although the electron emission element has the structure shown in FIG. 1A and 1B, the electrically conductive film 14 and the element electrode 12 and 13 which oppose each other are also laminated | stacked on the board | substrate 11 in order.

(Step B)

Then, the conductive film 14 is formed. By applying the organometallic solution, for example, the organometallic film is formed on the substrate 11 on which the electrodes 12 and 13 are arranged. The organometallic solution is a solution of an organometallic compound composed mainly of a metal selected as the material of the conductive film 14 described above. The organometallic film is baked and patterned by liftoff or etching to form the conductive film 14 (FIG. 2B). Although the organometallic film is formed by applying the organometallic solution in the above description, this application method is not limited, and the vacuum deposition method, sputtering process, chemical vapor deposition method, dispersion coating method, dipping method, spinner method, inkjet method and the like are conductive films. 14 can be used to form.

The inkjet method adds 10 ng to several tens of ng of liquid droplets to the substrate with high repeatability, thereby making the patterning of the conductive film by photolithography or vacuum process unnecessary. In order to form a conductive film by the inkjet method, a bubble jet type device using an electrothermal energy conversion element or a piezo-jet type device using a piezo element can be used as the energy generating element. Used as the calcination (baking) means for the above-mentioned liquid crystal droplets are electromagnetic wave radiating means, heating air blowing means, or means for heating the substrate as a whole. Usable as an electromagnetic wave radiation means are an infrared lamp, an argon ion laser, a semiconductor laser, etc., for example.

Materials for the conductive film 14 include metals such as Pd, Pt, Ru, Ag, Au, Ti, In, Cu, Cr, Fe, Zn, Sn, Ta, W and Pd, PdO, SnO2, In2O3, PbO, and Sb2O3 Oxides, such as HfB2, ZrB2, LaB6, CeB6, YB4 and GdB4, carbides such as TiC, ZrC, HfC, Ta, C, SiC and WC, nitrides such as TiN, ZrN and HfN, and Si or Ge It can be selected from semiconductors such as.

The film thickness of the conductive film 14 is appropriately set in consideration of the step coverage of the device electrodes 12 and 13, the resistance value between the device electrodes 12 and 13, and the like, and the thickness thereof is preferably severals to hundreds. It is in the range of nm, or more preferably in the range of 1 nm-50 nm. The resistance value Rs of the conductive film is preferably in the range of 1 × 10 2 to 1 × 10 7 Pa / □. The resistance value Rs of the conductive film is preferably in the range of 1 × 10 2 to 1 × 10 7 Pa / □. In order to calculate Rs, the resistance R of the thin film having the width w and the length l measured in the longitudinal direction is taken as R = Rs (1 / w).

(Step C)

The forming step is then performed to form the second gap 16 in the conductive film (conductive member) 14. Specifically, a gap 16 applied to the electrode pairs 12 and 13 to flow a current through the conductive film 14 to have local structural changes such as breakage, deformation or deterioration in a portion of the conductive film 14. To form (FIG. 2C). Although the conductive film 14 is completely separated into left and right cross sections in Fig. 2C, these cross sections may be partially connected to each other. Therefore, the conductive film 14 in which the gap 16 was formed in the forming step described above has a pair of conductive films (conductive members) or gaps 16 that face each other with the gap 16 interposed therebetween (conductive members). 14).

3 shows an example of the voltage waveform for the energization processing described above. In Fig. 3, the pulse width T1 is freely set within the range of 1 ms to 10 ms, and the pulse interval T2 is set freely within the range of 10 ms to 10 ms. The pulse height is selected according to the thickness of the material and the conductive film. Under the conditions described above, the pulse voltage is applied for a few seconds to several tens of minutes. When the current value during voltage application is preliminarily measured, a current value that does not exceed any set value is useful for determining whether the formation of the gap 16 has been completed. For example, the resistance value is determined by measuring a current supplied by applying a voltage of about 0.1 V, and the formation is terminated by stopping the current when the resistance value exceeds 1 mA.

(Step D)

The activation step is performed to form a carbon film 15 having a main component of carbon formed on the conductive film 14 on which the second gap 17 is formed as described above (FIG. 2D). Device current If and emission current Ie can be increased significantly at this stage.

According to the present invention, the electron emitting means 41 is disposed separately outside the electron emitting element shown in FIG. 4 in the activation step, and the carbon film 15 of which carbon is the main component is a gap 16 with the electron beam emitted from the electron emitting means. Is applied by applying a voltage across the electrodes 12 and 13 while irradiating any one of the regions (1) to (3) to be described below. That is, the application of voltage to the electrodes 12 and 13 is carried out simultaneously by irradiating an electron beam from the electron emitting means.

The region irradiated with the electron beam described above

(1) the substrate 11 in the gap 16 described above

(2) the substrate 11 in the gap 16 and the conductive film 14 in the vicinity of the gap 16 or

(3) The substrate 11, the conductive film 14, and the electrodes 12 and 13 in the gap 16 described above. It is preferable to irradiate the above-mentioned region 3 with an electron beam.

In addition, it is preferable to repeatedly apply the pulse voltage in the above-mentioned activation step of applying a voltage to the electrodes 12 and 13. Moreover, the present invention preferably applies the positive pulse voltage shown in Fig. 2D or 22B.

The carbon film 15 repeatedly applies pulse voltages across the conductive film 14 (electrode pairs 12 and 13) in an atmosphere containing a carbon compound gas (organic material gas) and is spaced apart from the electron emission element. It can be formed by irradiating near the gap 16 with the electron beam emitted from the emitting means 41.

4 schematically shows the apparatus used to irradiate near the gap 16 with an external electron beam. In Fig. 4, reference numeral 41 denotes an electron emitting means. The electron emitting element and the electron emitting element 41 are disposed in the same vacuum bezel. Useful as the electron emitting means 41 is a structure for accelerating the electron beam by applying an acceleration voltage using a hot electron cathode as the electron beam source.

It is not necessary to focus the electron beam emitted from the electron emitting means 41 only on the gap 16, but in the vicinity of the gap 16 considering the voltage applied across the electrodes 12, 13 and the partial pressure of the carbon compound gas in the activation step. It is preferable to diffuse the electron beam of several micrometers or more at.

However, when the electron beam is irradiated on a large area, the carbon compound may be deposited on the unnecessary area. Therefore, it is preferable to shield the electron beam emitted from the electron emitting means 41 with the electron beam shielding means 42 to suppress the diffusion of the electron beam.

It is preferable to set the above-mentioned acceleration voltage to 1 kV to 20 kV. That is, it is preferable to irradiate the said area | region with the electron beam which has an energy of 1 KeV or more and 20 KeV or less. The electron beam may be emitted as a DC voltage or as a pulse in synchronization with the pulse voltage applied across the electrodes 12 and 13 described above. It is preferable to apply a pulse voltage to the above-mentioned element electrode while continuously emitting an electron beam (like a DC voltage).

In the activation step of the present invention, it is preferable to apply a voltage to the element electrodes 12 and 13 while irradiating with the electron beam emitted from the electron emitting means 41. That is, any one of the regions (1) to (3) described above is irradiated with the electron beam emitted from the electron emitting means while voltage is applied to the element electrodes 12 and 13.

The carbon film 15 formed in the activation step of the present invention is connected to the electrodes 12 and 13 described above or directly by the conductive film 14, respectively.

In addition, the conductive films (carbon films) 15 formed in the above-mentioned activation step are opposed to each other and have a first gap 17 interposed therebetween as shown in FIG. 2D. Although the carbon film 15 takes the first gap 17 as the boundary in FIG. 2D and is completely separated into left and right cross sections, the films can be partially connected to each other. Accordingly, the carbon film 15 formed in the activation step may be a carbon film (conductive member) 15 having a pair of carbon films or gaps 17 facing each other with the gap 17 interposed therebetween.

Examples of the carbon compound (organic substance) to be contained in the atmosphere in the above-mentioned activation step include aliphatic hydrocarbons such as alkanes, alkenes and alkynes, aromatic hydrocarbons such as alcohols, aldehydes, ketones and amines, and phenols, carboxylic acids and sulfonic acids. Organic acids, ie specifically useful carbon compounds, are saturated hydrocarbons such as methane, ethane and propane, unsaturated hydrocarbons such as ethylene and propylene represented by the structural formula of CnH2n, benzene, toluene, methanol, ethanol, formaldehyde , Acetaldehyde, acetone, methyl ethyl ketone, methylalmine, ethylamine, phenol, formic acid, acetic acid, propionic acid or mixtures thereof.

In the conventional activation step described above, the carbon compound present in the atmosphere is decomposed only by the current supplied through the second gap 16 and the carbon and / or carbon compound is separated from the substrate and the gap 16 in the second gap 16. The electrons deposited on the adjacent conductive film 14 and emitted from the vicinity of the gap 16 (the gap 17 formed) irradiate the carbon or carbon compound and crystallize a portion of the carbon or carbon compound to impart electrical conductivity. It is considered to be.

The crystal structure of the carbon film 15 obtained in the activation step includes a graphite structure and / or an amorphous structure. In addition, the carbon film 15 may have an intermediate structure in its forming process. The carbon film 15 may have a high electrical conductivity when it has a graphite structure, but the electrical conductivity decreases when the film is an amorphous structure. The degree of crystal has a strong influence on the properties of the electron emitting device, in particular the electron emission efficiency to be described later.

Crystallinity refers to the degree of progress of a material so that the repeating structure changes from amorphous conditions through relatively markedly disturbed conditions for the perfect crystalline structure.

In addition, the conventional activation step attempts to deposit carbon or carbon compounds deposited in the gap 16, in particular to a relatively narrow gap in the gap 16 as the step proceeds. As a result, the carbon film 15 is formed in a "disordered" structure.

Therefore, the conventional manufacturing method produces a "disordered" structure of the carbon film 15 as the activation step proceeds, so that some positions of the deposited carbon or carbon compound are not sufficiently irradiated with electrons emitted from the vicinity of the gap 16. . Under these conditions, the film of carbon or carbon compound deposited near the gap 16 grows under conditions including a plurality of regions having a low crystallinity, and thus the carbon film 15 thus obtained has a low conductivity. The low conductivity is considered to be the result caused by insufficient irradiation with the electron beam in the growth phase of the carbon film 15.

When the carbon film includes several regions having a low grade crystallinity as described above, the crystal structure of the carbon film 15 is caused by the impact of electrons emitted from the electron emitting region or by the device current If. It is considered that due to heat generation it changes gradually, thereby changing the grade of crystallinity from the amorphous structure to the graphite structure. In addition, it is considered that the resistance of the carbon film 15 changes at the same time, thereby gradually changing the electrical conduction characteristics of the device.

The change in the electrically conductive property causes a change in the electron-emitting property of the device, thereby allowing a change in brightness in order for the image forming apparatus to have a plurality of devices preferably having uniform properties.

In contrast, in the method of manufacturing the electron emission device according to the present invention using the electron beam from the outside of the device, the electron beam can be sufficiently irradiated to the carbon film formed in the second gap 16. Therefore, the manufacturing method according to the present invention accelerates the change in the physical properties of the carbon film, thereby effectively forming an electrically conductive film mainly composed of a carbon film having a sufficiently high grade of crystallinity and high electrical conductivity. As a result, the manufacturing method according to the present invention can limit the deterioration of the physical properties of the carbon film during driving as described above. Thus, the manufacturing method according to the invention stabilizes the electron emission characteristics of the device.

In the production method according to the present invention, the specific resistance of the electrically conductive film (carbon film) mainly containing carbon can be controlled to 0.001 mmm or less.

Moreover, the method for producing an electron source according to the present invention allows the electron emission region to be irradiated using the electron beam emitted from the electron emission region of the adjacent electron emission device as the electron beam. This technique eliminates the need to deploy separate electron emitting means for electron beam irradiation as shown in FIG.

When the reaction to form the carbon film is irregular by the "disordered" structure, the carbon film 15 can be produced even when forming a partially thick shadowed area where electrons can hardly be irradiated. The manufacturing method according to the present invention arranges the external electron emitting means as described above to receive the electrons from other adjacent devices so that light can be irradiated to the carbon film at different angles.

Hereinafter, a description will be given of a technique using electron beams emitted from different electron emission devices.

An example in which two devices using a device electrode in common are arranged adjacent to each other will be described.

When the two electron emitting devices are adjacent to each other, the electron beam emitted from the electron emitting region of the other electron emitting apparatus can be irradiated in the vicinity of the electron emitting region of the electron emitting apparatus, whereby the electron beam is irradiated to the electron emitting region. In the process, a carbon film (electrically conductive film) mainly containing carbon is formed. At this time, since the electrons are emitted from the cathode side to the anode side, the electrons emitted from the two electron emitting devices can be aligned with each other to guide the electrons to the electron emitting region of the electron emitting device with higher efficiency. By a structure in which one of the device electrodes is jointly used by two electron emitting devices adjacent to each other or in particular a structure in which one device electrode of the electron emitting device is electrically connected to one electrode of the other electron emitting device, This embodiment allows each of the electron emitting devices to irradiate the electron emitting regions of the other electron emitting devices. In other words, the direction of electron emission is adjusted by setting the commonly used device electrodes or connected device electrodes to the ground potential and applying a voltage having a phase difference of π out of phase to the pair of electrodes. The electron beam emitted from another electron emitting region can be irradiated in the vicinity of the electron emitting region by being completely matched with each other. As a result, an electrically conductive film (carbon film) mainly composed of carbon can be effectively formed on two electron emission regions.

7A and 7B are schematic diagrams showing the configuration of the electron source used in this embodiment, in which Fig. 7A is a plan view and Fig. 7B is a sectional view. In Figs. 7A and 7B, reference numeral 71 denotes a substrate on which the common device electrode 72 and the device electrodes 73 and 74 are formed. The electrically conductive film 75, the electron emission region 79 and the carbon film 76 are a pair of device electrodes (referred to as electrode pair A) constituting the common device electrode 72 and the device electrode 73. It is formed between and constitutes the electron emission apparatus A. FIG. Furthermore, the electrically conductive film 77, the electron emission region 80, and the carbon film 78 constitute a pair of reference devices (referred to as device electrode pairs B) constituting the common device electrode 72 and the device electrode 74. It is formed between device electrodes to constitute an electron emitting device (B).

The electron source may be regarded as having a basic structure in which two electron emitting devices are arranged in series by the common device electrode 72 to form a device similar to that described with reference to FIGS. 1A and 1B.

The electrodes 72 to 74 and the electrically conductive films 75 and 77 of the electron emitting device described above are formed in the same manner as the method of forming the above-described electron emitting device. Moreover, the spacing L1 between the electrodes, and the length W and the film thickness of the electrodes are determined in consideration of the electron emission efficiency. In FIGS. 7A and 7B, the two electrode pairs have the same spacing L1 and the three electrodes have the same length. In addition, the width L2 of the cavity device electrode 72 is set in consideration of the distance at which the electron beam emitted from the electron emission region can be irradiated to each of the adjacent electron emission regions. The overlap width of the device electrodes on the electrically conductive film is selected to such an extent that electrical conductivity can be established between these members.

The electron emission regions 79 and 80 ground the common device electrode 72 and connect the device electrode 73 to the device electrode 74 to set these electrodes to the same potential and apply voltage to the electrode pairs A and B. It can be formed at the same time by applying at the same time.

For the activation process of two electron emitting devices adjacent to each other as shown in Figs. 7A and 7B, the device can be irradiated by an electron beam emitted from another device. Specific procedures for electron beam irradiation will be described below.

The common device electrode 72 is grounded and a pulse voltage source (not shown) is connected to the device electrodes 73 and 74.

8A and 8B illustrate voltage waveforms a and b of rectangular pulses of AC voltages applied to the device electrode 73 and the device electrode 74, respectively. As shown in Figs. 8A and 8B, pulse voltages having a phase difference of π are applied to the electrodes, respectively.

Now, electrons and some of the electrons flowing in the direction from the electrode at the relatively low potential toward the electrode at the high potential through the electron emission region are emitted as the electron beam in the same direction. Thus, when voltages such as those shown in FIGS. 8A and 8B are applied, the electron beam is directed from the electron emitting region 79 to the electron emitting region 80 and from the electron emitting region 80 to the electron emitting region 79. Are released alternately in the direction of.

9A and 9B schematically illustrate a method of alternately emitting electron beams. At each time the pulse voltage changes, the direction of the electron beam is changed as shown in Figs. 9A and 9B. In the case of FIG. 9A, the electron beam emitted from the electron emission region 79 is irradiated near the electron emission region 80. In the case of FIG. 9B, the electron beam emitted from the electron emission region 80 is irradiated near the electron emission region 79.

As other pulse patterns, voltage waveforms such as those shown in FIGS. 10A and 10B may be used. In this case, pulse voltages having different π / 2 phases from each other are applied to the device electrodes 73 and 74, respectively. This waveform pattern prevents the electron beam from being emitted from the electron emitting region while the electron beam is emitted to another electron emitting region and allows the electron source to receive the electron beam only in any direction, thereby between the electron beams emitted in two directions. Prevent interference from occurring.

In addition, the present invention provides a manufacturing method which will be described later, which can reduce the change in characteristics between devices caused by meandering of the second gap 16 produced in the forming step.

That is, another embodiment of the present invention directly performs the activation step between a pair of device electrodes (electrically conductive members) 12 and 13 having relatively good linearity without using the aforementioned electrically conductive film 14. It is configured to be able to carry out. FIG. 21A is a schematic plan view of the electron emitting device in this embodiment, and FIG. 21B is a schematic cross sectional view of the electron emitting device. 22A, 22B and 23 are schematic diagrams showing partial processes of the above-described manufacturing method. Here, in the schematic diagrams shown in FIGS. 21A and 21B, the first gap 17 is shown in a complete straight line to facilitate understanding of the present invention. 21A and 21B, although the carbon film 15 is completely separated from the first gap 17 as a boundary, the carbon film 15 may be partially connected. Accordingly, the carbon film 15 formed in the above-described activation step may be a carbon film 15 having a pair of carbon films 15 or a gap 17 facing each other through the gap 17.

Another manufacturing method described above according to the present invention is configured to provide a pair of device electrodes (electrically conductive member) 12 and 13 with a gap L interposed on the substrate 11 (FIG. 22A). In this embodiment, the gap between the device electrodes 12 and 13 corresponds to the first gap 16 described above.

At this time, the activation step according to the present invention is carried out. In this activation step, the electron emitting means are arranged separately and apply voltage to the electrodes 12 and 13 while irradiating one of the regions 1 and 2 described below by the electron beam emitted from the electron emitting means. The carbon film 15 is formed by applying (FIGS. 22B and 23). In other words, a voltage is applied to the electrodes 12 and 13 by simultaneously irradiating the electron beam from the electron emitting means.

The region to which the above-mentioned electron beam is irradiated is one of the following regions.

(1) the substrate 11 between the device electrodes 12 and 13 described above, or

(2) the device electrodes 12 and 13 described above and the substrate 11 between the electrodes 12 and 13.

Thus, the present embodiment is not only a first gap 17 between the device electrodes 12 and 13 but also an insulating substrate between the carbon film 15 and the device electrodes 12 and 13 on the device electrodes 12 and 13. (11) can be formed.

Fig. 23 is a schematic diagram showing an apparatus for irradiating an external electron beam. The electron irradiation apparatus shown in FIG. 23 has a configuration basically the same as that of the apparatus shown in FIG. In Fig. 23, reference numeral 51 denotes an electron emission means. Even when the electron-emitting means 51 is disposed in the vacuum container of the electron-emitting device, the electron-emitting means is housed in a separate vacuum container separate from the vacuum container containing the substrate 11 and the electron-emitting means are individually. Venting may be required.

When the electron-emitting means are individually evacuated, the electron beam penetrating pinhole (52 in FIG. 23) receives the electron-emitting means 51 due to the low conductivity of the pinhole due to the internal pressure of the vacuum vessel containing the substrate 11. It is formed to be separated from the internal pressure of the vacuum vessel.

A structure that uses hot electrons as the electron source and accelerates the electron beam by applying an acceleration voltage can be used as the electron emitting means 51. In addition, an electron beam shielding means 52 is provided to finely control the region to which the electron beam is irradiated.

The substrate 11 between the device electrodes 12 and 13 and / or the device electrodes may be irradiated with an electron beam such as a DC voltage or a pulse voltage in synchronization with a pulse voltage applied to the electrodes.

Thus, the present invention uses an electrically conductive film 14 (shown in FIGS. 1A and 1B) electrically connected to the device electrodes and forms a second gap 16 in the electrically conductive film required in the activation step. The "forming step" is unnecessary.

In other words, the present invention provides the carbon film 15 and the first gap at an interval L (a few micrometers to several tens of micrometers) between the electrodes wider than the second gap 16 described above by irradiation of an external electron beam. (17) can be arranged. In addition, the second gap 16 formed in the apparatus shown in FIGS. 21A and 21B corresponds to the spacing between the electrodes 12 and 13. Thus, the second embodiment allows the second gap formed in the apparatus to have a high linearity and a high uniformity width (L).

Thus, the second embodiment is characterized by the nonuniformity of the width of the second gap 16 described above and the nonuniformity of the distance from the device electrodes 12 and 13 to the second gap in the device shown in FIGS. 19A-19D or 20. It is possible to reduce local fluctuations in the electron emission characteristics of the electron emission device caused by. Moreover, the second embodiment also exhibits the above-described electron beam emission effect, whereby the electron emission efficiency of the device can be improved to significantly reduce the variation or deterioration of characteristics while driving the device.

In addition, the method of manufacturing an electron emitting device according to the present invention uses the electrically conductive film 14 electrically connected to the device electrodes and also forms the second gap 16 in the electrically conductive film required in the conventional activation step. The "forming step" to do so is unnecessary, thereby simplifying the configuration of the apparatus and reducing the number of processes. That is, in the manufacturing method according to the present invention, it is possible to efficiently and efficiently manufacture an electron emitting device having a stable and high efficiency electron emitting effect. Moreover, in the manufacturing method according to the present invention, it is possible to provide an electron source and an image forming apparatus including the electron emitting devices arranged on the substrate and having high uniformity, high efficiency and stable characteristics.

In the activation step of the manufacturing method according to the invention, it is particularly preferred to apply a voltage to the device electrodes 12 and 13 while the electron beam is irradiated from the electron emitting means 41, 51. In other words, it is preferable to perform irradiation by the electron beam emitted from the electron emitting means while the voltage is applied to the device electrodes 12 and 13. This technique makes it possible to improve the grade of crystallinity of the carbon and / or carbon compound forming the first gap 17 in the initial deposition step. In more detail, compared to the conventional activation method, the carbon and / or carbon compound shows device electrodes 12 and 13 because electrons with high energy are projected separately from the electron emitting means 41, 51. Can be deposited as a carbon film having a high degree of crystallinity from the initial deposition step by the current applied between them. Thus, for example, it can be expected that the gap 17 is formed with a narrower width, whereby a device having excellent characteristics is formed.

(Step E)

5) It is preferable to perform the activation step for the electron emitting device obtained through the activation step according to the present invention described above. This step exhausts the organic material from the vacuum vessel. In order to evacuate the vacuum vessel, it is preferable to use a vacuum evacuation apparatus without oil so that the oil does not affect the characteristics of the apparatus. In detail, a vacuum evacuation device such as an adsorption pump, an ion pump, or the like may be used to evacuate the vacuum vessel.

If an oil diffusion pump or a rotary pump is used as the exhaust device and the organic gas resulting from the oil component supplied from the pump is used in the above-mentioned activation step, it is necessary to keep the partial pressure of these components at a low level. When the carbon or carbon compound is newly deposited, the partial pressure of the organic component in the vacuum vessel is preferably set at a level not higher than 1 × 10-6 Pa, in particular at a level where the partial pressure is not higher than 1 × 10-8 Pa. It is more preferable to set. In the evacuating of the vacuum vessel, it is preferable to heat the vacuum vessel as a whole to discharge the organic material molecules adsorbed by the inner wall of the vacuum vessel and the electron emission device. It is preferable to evacuate the vacuum container at 80 to 300 ° C., but it is preferable to make the time as long as possible at 150 ° C. or higher, but this condition is not limited, and conditions such as the size and shape of the vacuum container and the configuration of the electron emitting device, etc. The vacuum vessel can be evacuated under conditions appropriately selected according to the above. The vacuum vessel is preferably evacuated at an extremely low level that does not exceed 1 × 10 −5 pa and more preferably does not exceed 1 × 10 −6 pa.

For driving after the stabilization step described above, it is preferable to maintain the atmosphere after the end of the stabilization step, but this atmosphere is not limited to this, and even if the pressure itself becomes slightly higher, it is possible to maintain stable characteristics if the organic material can be sufficiently removed. have. By adopting such an atmosphere, the carbon and the carbon compound can be prevented from being deposited again, whereby the device current If and the discharge current Ie can be stabilized.

Now, the basic characteristics of the electron-emitting device according to the present invention will be described in detail. 5 is a schematic diagram illustrating an apparatus for evaluating basic characteristics of an electron-emitting device according to the present invention. The evaluation device has a function of evaluating the system as well as evaluating device characteristics of measuring the system. In Fig. 5, elements such as those shown in Figs. 1A and 1B are denoted by the same reference numerals as those used in Figs. 1A and 1B. Specifically, reference numeral 11 denotes a substrate constituting the electron-emitting device, reference numerals 12 and 13 denote electrodes, reference numeral 14 denotes an electrically conductive film, and reference numeral ( 100 indicates an electron emission region. The carbon film 15 was deleted for convenience. In addition, reference numeral 51 denotes a power source for applying the device current If to the electron-emitting device, and reference numeral 50 measures the device current If provided through the electrically conductive film between the electrodes 12 and 13. Reference numeral 54 denotes a cathode for capturing the emission current Ie emitted from the electron emission region of the device. Reference numeral 53 denotes a high voltage power source for applying a voltage to the cathode 54, and reference numeral 52 denotes an ammeter for measuring the emission current Ie emitted from the electron emission region 16 of the device. The basic characteristics of the device according to the invention are measured while applying a voltage of 1 kilovolt to the cathode and maintaining a distance H of 2 millimeters between the cathode and the electron-emitting device.

In order to measure the basic properties, the vacuum vessel is first emptied to prevent new precipitation of carbon or carbon compounds, and the oil-free vacuum evacuation device, for example the adsorption pump, results in the oil of the device It is used as the vacuum discharge device 56 for emptying the vacuum container 55 which does not affect the characteristics of the.

The partial pressure of the organic component in the vacuum vessel 55 is set at a level which does not exceed 1 x 10 &lt; -8 &gt; Pa, in which the above-described carbon and carbon compound are not newly deposited. In this case, it is preferable to heat the vacuum vessel to 200 ° C. or higher in order to facilitate the discharge of the molecules of the organic component absorbed by the electron emitting device and the inner surface of the vacuum vessel.

FIG. 6 is a schematic diagram showing the relationship between the emission current Ie, the device current If, and the device voltage Vf of the electron-emitting device according to the present invention measured by the discharge device shown in FIG. In Fig. 6, the emission current Ie is marked in arbitrary units because it is significantly smaller than the device current If.

Also apparently from Fig. 6, the electron-emitting device according to the present invention has three characteristics related to the emission current Ie as described below.

Firstly, the electron-emitting device suddenly increases when the device voltage exceeds a certain voltage level while the emission current Ie is mostly emitted when the voltage level does not exceed the threshold voltage Vth. Currently, the electron-emitting device according to the present invention is a non-linear device having the threshold voltage which is exactly proportional to the emission current Ie.

Secondly, the emission current Ie can be controlled by the device voltage Vf because it slowly increases by the device voltage Vf.

Third, the amount of emission electrons captured by the cathode 54 (shown in FIG. 5) depends on the time for applying the device voltage Vf. In other words, the amount of electrons captured by the cathode 54 can be controlled by the time for applying the device voltage Vf.

As understood from the foregoing description, the electron-emitting device according to the present invention has an electron emission characteristic which can be easily controlled depending on the input signal. Using this feature, the electron-emitting device according to the present invention is applicable to various applications such as an image-forming device constructed by arranging a plurality of electron sources and electron-emitting devices.

FIG. 6 shows an embodiment in which the device current If is also slowly increasing by the device voltage Vf (hereinafter referred to as the “MI characteristic”), but the device current If is opposed to the resistance characteristic (hereinafter referred to as the “VCNR characteristic). The type of voltage control will be described in. These characteristics can be controlled by adjusting the steps described above.

The electron-emitting device having the unique characteristics described above and according to the present invention can easily control the amount of electrons emitted from the image-forming device consisting of arranging a plurality of the electron source or the electron-emitting device, and various It can be used for applications.

Application embodiments of the electron-emitting device according to the present invention will be described later. The electron source or image-forming device can be constructed by arranging the electron-emitting device according to the invention in the majority of substrates.

Various arrangements of electron-emitting devices will be employed. For example, most of the electron-emitting devices may be arranged in parallel, and ladder types having both ends connected to each other, electron-emitting devices arranged in many lines (one direction), and one-way and the above-mentioned electron-emitting devices. There are electrons of the electron-emitting device that are controlled and move with electrodes (lattice electrodes) lying in a vertical direction (row direction). Independently of this arrangement, the arrangement is different from that of a plurality of electron-emitting devices arranged in a matrix, generally a line connected with wires in the X direction, and a plurality of electron-emitting devices generally connected with wires in the Y direction. There are a number of electron-emitting devices arranged in the X and Y directions to form a kind of electrode. Such an array is called a simple matrix array. The simple matrix arrangement will be described later.

The electron-emitting device according to the present invention has three characteristics as described above. Specifically, the electrons emitted from the electron-emitting device can be controlled by the amplitude and width of the pulse voltage applied to the device electrodes opposite to each other up to a voltage exceeding the threshold voltage. On the other hand, the voltage does not exceed the threshold voltage, that is, most of the electrons are emitted from the electron-emitting device. This property makes it possible to control the amount of emitted electrons dependent on the input signal by selecting an electron-emitting device and applying an appropriate pulse voltage to each of the electron-emitting devices when many of them are arranged. do.

Referring to Fig. 12, an electron source substrate obtained by arranging the plurality of electron-emitting devices according to the present invention will be described. In Fig. 12, reference numeral 121 denotes an electron source substrate, reference numeral 122 denotes a wire in the X direction, and reference numeral 123 denotes a wire in the Y direction. Reference numeral 124 denotes an electron-emitting device according to the invention and reference numeral 125 denotes wiring.

The wire 122 in which m elements Dx1, Dx2, ... Dxm are arranged in the X direction is composed of an electrically conductive metal or the like formed by a vacuum deposition method, a printing method or a sputtering process. In any material, the film thickness and width of the wire is appropriately designed. The wire 123 in which n elements Dy1, Dy2, ... Dyn are arranged in the Y direction is formed similarly to the wire 122 in the X direction. An insulating layer (not shown) is used to separate the wires 122 from the wires 123, m wires 122 in the X direction, and n wires 123 in the Y direction (m and n are positive integers). Formed between).

The insulating layer (not shown) consisting of SiO 2 or the like is formed by the vacuum deposition method, printing method or sputtering process. The insulating layer is formed, for example, in the required shape on the whole or part of the surface of the substrate 121 of the wire 122 formed in the X direction, and the thickness, material and manufacturing method of the layer consequently result in the layer. The electric potential difference at the portion intersecting between the wire 122 in the X direction and the wire 123 in the Y direction is selected. The wire 122 in the X direction and the wire 123 in the Y direction are drawn to the external terminal, respectively.

The pair of device electrodes (not shown) constituting the electron-emitting device 124 are electrically connected to the m wires 122 in the X direction and the Y direction through the wiring 125 made of an electrically conductive metal or the like. N wires 123 are connected.

All or some of the components of the material used to form the wire 122 in the X direction, the wire 123 in the Y direction, the wiring 125 and the device electrode will be the same or different from each other. Such material is suitably selected from, for example, the materials for the device electrodes described above. When the materials of the device electrode are the same as those of the wire, the wires connected to the device electrode will be called the device electrode.

The wire 122 in the X direction is connected to a scanning signal applying device (not shown) that applies a scanning signal to select a line of the electron-emitting device 124 arranged in the X direction. In other words, the wire 123 in the Y direction is connected to a modulation signal generator (not shown) that modulates each row of the electron-emitting device 124 arranged in the Y direction along the input signal. A driving voltage is applied to each electron-emitting device by the voltage difference between the scanning signal and the modulation signal applied to the electron-emitting device.

The above described configuration makes it possible to select individual devices and drive the devices independently using simple matrix wiring.

13, 14 and 15, an image-forming apparatus formed using an electron source such as a simple matrix arrangement will be described in detail. FIG. 13 is a schematic diagram showing an embodiment of a display panel of the image-forming apparatus, and FIGS. 14A and 14B are schematic diagrams showing a fluorescent film used in the image-forming apparatus shown in FIG. 15 is a block diagram illustrating a driving circuit for a display that follows a TV signal of an NTSC system. Components such as those shown in FIG. 12 are represented by the same reference numerals and are not actually shown. For convenience, the electrically conductive film 14 and the electrically conductive film 15 are deleted.

In FIG. 13, reference numeral 131 denotes a rear plate to which the electron source substrate 121 is fixed, and reference numeral 136 denotes a fluorescent film 134 and a metal formed on an inner surface of the glass substrate 133. An anterior plate with membrane 135 and the like is shown. Reference numeral 132 denotes a support frame to which the rear plate 131 and the front plate 136 are connected using molten glass or the like. Reference numeral 138 denotes an enclosure configured by bonding within the 400 to 500 ° C. temperature range, for example, for 10 minutes or longer.

The enclosure 138 consists of the front plate 136, the support frame 132 and the rear plate as described above. Since the back plate 131 is mainly placed to reinforce the electron source substrate 121, the back plate 131 is unnecessary when the substrate 121 itself has sufficient strength. Specifically, the support frame 132 will be sealed directly to the substrate 121, the enclosure 138 is the front plate 136, the support frame 132 and the substrate 121 It will consist of. In other words, the enclosure 138 is configured to have sufficient strength against atmospheric pressure by placing a support component called a spacer (not shown) between the front plate 136 and the rear plate 131. Can be.

14A and 14B are schematic diagrams showing fluorescent films. The fluorescent film 134 may be made of a fluorescent material when the film is monochromatic. The color fluorescent film may be comprised of a black electrically conductive material 141 called black stripe (FIG. 14A) or black matrix (FIG. 14B) and fluorescent material 142. The black stripe or the black matrix is arranged to make the color mixing not stand out by the black coated edges among the three primary color fluorescent materials 142 essential for color display and reflected by the fluorescent film 134. The contrast is prevented from being lowered by the external rays. Among the black electrically conductive materials 141 that can be used are materials that are electrically conductive and mostly transmitted or reflect light, and in addition, are materials having graphite as an important component generally used.

In the placement method, a printing method or a similar method may be employed to apply the fluorescent material to the glass substrate 133 whether the film is monochromatic or multicolored. The metal film 135 is generally disposed on the inner surface of the fluorescent film 134. The purpose of disposing the metal film is to enhance the light brightness of moving the light emitted from the fluorescent material toward the glass substrate 133 by the mirror reflection toward the outside of the inner surface, and to accelerate the voltage of the electron beam. It is to make light as an electrode for the application, and to protect the fluorescent material from damage caused by the impact of negative ions produced in the enclosure. The metal film is prepared by smoothing (generally named "pilling") the inner surface of the fluorescent film which deposits Al by vacuum deposition or the like after forming the fluorescent film.

Furthermore, the front plate 136 includes a transparent electrode (not shown) disposed on an outer surface of the fluorescent film 134 to enhance the electrical conductivity of the fluorescent film 134.

In the case of the color fluorescent film, it is essential that each electron-emitting device carries a fluorescent material of each color, and sufficient positioning is indispensable for the above-mentioned sealing step.

The image forming apparatus shown in FIG. 13 is manufactured, for example, as described below.

The enclosure 138 does not use oil as its exhaust inside the ion pump or the stabilization stage described above until it is filled with an atmosphere of 1 × 10-5 Pa vacuum and contains sufficiently small organic matter. It is sealed after being emptied during proper heating with a drainage device such as an adsorption pump. Getter processing is performed to maintain a vacuum after closing the enclosure 138. This is done to seal the enclosure 138 and to form the placed film by heating a getter (not shown) disposed in a predetermined position within the enclosure 138 with a resistance heater or a high frequency heater. The getter generally has an important element of Ba or the like and serves to maintain a high vacuum not lower than 1 × 10 −5 Pa, for example by adsorbing the function of the placed film.

In the next step, an embodiment of configuring a driving circuit for a TV display with a TV signal of the NTC system on a display panel constructed by using the electron source of the simple matrix arrangement as shown in FIG. 15 will be described. In Fig. 15, reference numeral 151 denotes a display panel, reference numeral 152 denotes a scanning circuit, reference numeral 153 denotes a control circuit, reference numeral 154 denotes a shift register, and reference Reference numeral 155 denotes a linear memory, reference numeral 156 denotes a simultaneous signal separator circuit, reference numeral 157 denotes a modulated signal generator, and reference symbols Vx and Va denote DC voltage sources.

The display panel 151 is connected to an external electrical circuit via terminals Dx1 through Dxm and via Dyn1 and high voltage terminal 137 through Dyn. Terminal Dx1 applied through Dxm drives an electron source disposed within the display panel 151 that is continuously driven by aligning (n devices) a group of wired electron-emitting devices in m lines and n row matrices. Is a scanning signal. The terminal Dy1 applied via Dyn is a modulation signal for controlling the electron beam output from the electron-emitting device in the line selected by the scanning signal. Provided from the DC voltage source Va to the high voltage terminal 137 is an accelerating voltage, 10 kilovolts, which provides an electron beam emitted from the electron-emitting device with sufficient energy to excite the DC voltage, for example the fluorescent material.

Now, the scanning circuit 152 will be described in detail. This circuit consists of n switching elements (shown schematically by S1 to Sm in FIG. 15). The switching elements select the output voltage from the DC voltage source Vx or 0 volts (ground state) and are electrically connected to the terminal Dx1 via Dxm to the display panel 151. Sm in switching element S1 may be configured by operating on the basic control signal Tscan output from the control circuit 153 and in combination with a switching element such as, for example, a FET.

Based on the characteristics of the electron emitting device (threshold voltage for electron emission), the DC voltage source Vx uses such a constant voltage to maintain the driving voltage applied to the non-scanned device below the threshold voltage for electron emission. It is set to output.

The control circuit 153 has a function of matching the operations of the members so that the image is appropriately displayed based on the image signal input from the outside. The control circuit 153 generates control signals Tscan, Tsft, and Tmry for the members based on the synchronization signal Tsync transmitted from the synchronization signal separator circuit 156.

The synchronization signal separator circuit 156 is a circuit for separating the synchronization signal component and the luminance signal component from the TV signal of the NTSC system input from the outside, and may be configured as a general frequency separator circuit (filter). The synchronization signal separated by the synchronization signal separator circuit 156 consists of a vertical synchronization signal and a horizontal synchronization signal, but for the sake of convenience, the synchronization signal is denoted by Tsyn. The luminance signal component of the image separated from the TV signal is represented as a DATA signal for convenience. This DATA signal is input to the shift register 154.

The shift register 154 is used for per line serial / parallel conversion of the image of the above-described DATA signal input in time series, and operates based on the control signal Tsft transmitted from the control circuit 153 (ie, control). Signal Tsft can be referred to as the shift clock of shift register 154). The data (corresponding to n electron emitting elements) of the image line subjected to serial / parallel conversion processing is output as n parallel signals Id1 to Idn from the shift register 154.

The line memory 155 is a memory that stores the data of the image line for a required time and appropriately stores the contents of Id1 to Idn according to the control signal Tmry transmitted from the control circuit 153. The stored contents are output as Id'1 to Id'n and input to the modulated signal generator 157.

The modulated signal generator 157 is a signal source for appropriately driving and modulating each of the electron emission elements in accordance with the respective image data Id'1 to Id'n, and the output signal from the modulated signal generator 157 is connected to the terminals Dy1 to. Dyn) to the electron emission element in the display panel 151.

As described above, the electron emission device according to the present invention has the following basic characteristics of the emission current Ie. That is, the electron emitting device has an apparent threshold voltage Vth for electron emission and emits electrons only when a voltage higher than Vth is applied. At voltages above the threshold for electron emission, the emission current also changes depending on the change in voltage applied to the device. When a pulse voltage is applied to the electron emitting device, the device does not emit electrons when a voltage lower than the threshold for electron emission is applied, but when the high voltage is applied, the device emits electrons. At this stage, the intensity of the output electron beam can be controlled by changing the peak of the pulse. Furthermore, the total charge amount of the output electron beam can be controlled by changing the width Pw of the pulse.

Therefore, a voltage modulation system, a pulse width modulation system, or the like can be adopted as a system for modulating the electron emission element dependently on the input signal. In adopting a voltage modulation system, a voltage modulation type circuit that can generate a voltage pulse having a finite length and appropriately modulate the maximum value of the voltage pulse in dependence on the input data can be used as the modulation signal generator 157. In adopting the pulse width modulation system, a pulse width modulation circuit capable of generating a voltage pulse having a limited peak and suitably modulating the width of the voltage pulse in dependence on the input data can be used as the modulation signal generator 157. .

The shift register 154 and the line memory 155 may be a digital signal type or an analog signal type. This is because the shift register and the line memory are sufficient to perform serial / parallel conversion and storage operations of the image signal at a predetermined speed.

When a digital signal type shift register and a line memory are used, it is necessary to convert the output signal DATA from the synchronization signal separator circuit 156 into a digital signal. It is enough to just place a / D converter. With respect to these signals, the circuit to be used as the modulated signal generator 157 is slightly different depending on whether the line memory 155 is a digital signal or an analog signal. In the case of a voltage modulation system using a digital signal, for example, a D / A converter circuit is used as the modulation signal generator 157, and an amplifier circuit or the like is added as a normal requirement. In the case of a pulse width modulation system, for example, a circuit composed of a combination of a high speed oscillator, a counter for counting the number of waves output from the oscillator, and a comparator for comparing the output value from the counter with the output value of the memory is provided to the modulation signal generator 157. Is used. As a general requirement, an amplifier may be added that performs an operation of voltage amplifying a modulated signal pulse-width modulated and output from a comparator to a drive voltage of an electron-emitting device.

In the case of a voltage modulation system using an analog signal, an amplifier circuit using, for example, an operational amplifier or the like is used as the modulation signal generator 157, and a level shift circuit or the like can be added as a general requirement. In the case of a pulse width modulation system, a voltage controlled oscillator circuit (VCO) can be employed, and as a general requirement, an amplifier can be added that performs voltage amplification to the drive voltage of the electron-emitting device.

In the image forming apparatus according to the present invention, which can have the above-described configuration, electrons are emitted by applying a voltage to the electron emission element through the external terminals Dx1 to Dxm and Dy1 to Dyn of the sealing body. At the same time, the electron beam is accelerated by applying a high voltage to the metal back 135 or the transparent electrode (not shown) through the high voltage terminal 137. As the accelerated electrons impact the fluorescent film 134, the fluorescent film emits light to form an image.

The configuration of the above-described image forming apparatus can be variously changed based on the technique according to the present invention as an example of the image forming apparatus according to the present invention. Although the input signal of an NTSC system has been described above, it is not limited to this input signal, and may adopt a signal of a PAL system or a SECAM system, or other TV signal having a larger number of scanning lines (for example, a signal of a high quality TV such as a MUSE system). Can be.

Now, the above described ladder type electron source and image forming apparatus will be described with reference to FIGS. 16 and 17.

Fig. 16 is a schematic diagram of an embodiment of an electron source in a ladder configuration. In Fig. 16, reference numeral 160 denotes an electron source substrate, and 161 denotes an electron emission element. Reference numeral 162 denotes common wires D1 to D10 drawn out as external terminals for connecting the electron emission elements 161. The electron emission elements 161 are arranged in plural (called element lines) in parallel in the x direction on the substrate 160. A plurality of element lines are arranged to constitute an electron source. The device lines may be driven independently by applying a driving voltage to the common wire. Specifically, a voltage higher than the threshold voltage for electron emission is applied to the device line that will emit the electron beam, and a voltage lower than the threshold voltage for electron emission is applied to the device line that will not emit the electron beam. Among the device lines, for example, D2 and D3 of the common lines D2 to D9 may be integrated into a single wire.

17 is a schematic diagram illustrating a panel structure of an image forming apparatus including an electron source in a ladder configuration. Reference numeral 170 denotes a grid electrode, 171 denotes an opening through which electrons pass, D1 to Dm denote external terminals of the casing, and G1 to Gn denote external terminals of the casing connected to the grid electrode 170. Reference numeral 160 denotes an electron source substrate in which a common wire is integrated between the device lines. In Fig. 17, the same reference numerals and symbols are used for the same members as those shown in Figs. 13 and 16. For convenience, the conductive film 14 and the conductive film 15 are omitted. Unlike the image forming apparatus of the simple matrix configuration shown in FIG. 13, the image forming apparatus shown in FIG. 17 includes a grid electrode 170 disposed between the electron source substrate 160 and the face plate 136.

In FIG. 17, the grid electrode 170 is disposed between the substrate 160 and the face plate 136. The grid electrode 170 functions to modulate the electron beam emitted from the electron emission element 161, and is formed in a circular shape in a strip-shaped electrode disposed perpendicular to the element line of the ladder configuration so as to pass through the electron beam. ) There is one opening 171 for each element here. The shape and configuration of the grid electrode is not limited to that shown in FIG. For example, many meshed through holes may be formed as openings to place grid electrodes around or near the electron emitting device.

The outer terminals D1 to Dm and G1 to Gn of the casing are connected to a control circuit (not shown). Modulation signals for the image lines are simultaneously applied to the rows of grid electrodes line by line in synchronization with sequential scanning of the element lines. Therefore, the image forming apparatus can display image lines in units of lines by controlling the irradiation of the fluorescent material with each electron beam.

If so, the image forming apparatus according to the present invention described above can be used as an image forming apparatus configured as an optical printer using a photosensitive drum or the like as well as a display device for TV broadcasting, a TV conference system or a computer.

18 is a block diagram showing an example of an image forming apparatus according to the present invention configured to be able to display various image data sources, for example, image data supplied from a TV broadcasting station.

In Fig. 18, reference numeral 1700 denotes a display panel, 1701 denotes a driving circuit for a display panel, 1702 denotes a display controller, 1703 denotes a multiplexer, 1704 denotes a decoder, 1705 denotes an input / output interface circuit, 1706 denotes a CPU, 1707 denotes an image generating circuit, 1708 to 1710 are image memory interface circuits, 1711 are image input interface circuits, 1712 and 1713 are TV signal receiving circuits, and 1714 are input devices.

When the image forming apparatus receives a signal such as a TV signal including image data and audio data, of course, it reproduces audio while displaying an image, but receives, separates, and receives audio data not integrally related to the features of the present invention. Circuits and loudspeakers related to playback, processing and storage will not be described.

Now, the circuits in the flow order of the image signal will be described.

First, the TV signal receiving circuit 1713 is a circuit for receiving a TV signal transmitted through a wireless transmission system such as a wireless communication system or a spatial optical communication system. The system of the TV signal to be received is not particularly limited, and may be, for example, an NTSC system, a PAL system, or a SECAM system. Moreover, TV signals composed of more scan lines, for example, so-called high-quality TV signals such as those of the MUSE system, preferably take advantage of the advantages of display panels suitable for having large areas and many pixels.

The TV signal received by the TV signal receiving circuit 1713 is output to the decoder 1704.

Moreover, the TV signal receiving circuit 1712 is a circuit that receives a TV signal transmitted through a wired link transmission system such as a coaxial cable or an optical fiber. Like the TV signal receiving circuit 1713, the TV signal receiving circuit 1712 does not limit the system of the TV signal to be received, and the TV signal received by the TV signal receiving circuit 1712 is also output to the decoder 1704. .

The image input interface circuit 1711 is a circuit which takes an image signal supplied from an image input device such as a TV camera or an image reading scanner, and the image signal taken by this interface circuit is output to the decoder 1704.

The image memory interface circuit 1710 is a circuit which takes an image signal stored in a video tape recorder (hereinafter referred to as "VTR"), and the image signal taken by this circuit is output to the decoder 1704.

The image memory interface circuit 1709 is a circuit which takes an image signal stored in a video disk, and the image signal taken by this circuit is output to the decoder 1704.

The image memory interface circuit 1708 is a circuit which takes an image signal from an apparatus for storing still image data such as a still image disc, and the still image data taken by this circuit is output to the decoder 1704.

Input / output interface circuit 1705 is a circuit that connects the image forming apparatus to an external output device such as a computer, a computer network, or a printer. This circuit can input and output image data and character / picture data, and can enable input and output of control signals and numerical data between the CPU 1706 of the image forming apparatus and an external device.

The image generating circuit 1707 is configured to display image data and text / picture data input from the outside through the input / output interface circuit 1705 and image data and text / picture data output from the CPU 1706. It is a circuit to generate. The image generation circuit 1707 includes circuits necessary for image generation, such as a rewritable memory for storing image data and character / picture data, a read-only memory for storing image patterns corresponding to character codes, and a processor for image processing. It is built.

The image data to be displayed generated by this circuit is output to the decoder 1704 and, in certain cases, can be output to an external computer network or a printer through the above-described input / output interface circuit 1705.

The CPU 1706 mainly controls the operation of the image display device, and performs tasks related to generation, selection, and editing of images to be displayed.

For example, the CPU 1706 outputs a control signal to the multiplexer 1703 and appropriately selects and combines image signals to be displayed on the display panel. In this step, the CPU 1706 generates a control signal for the display panel controller 1702 in accordance with the image signal to be displayed, so as to display the screen display frequency, the scanning mode (eg, interlaced or non-interlace), and The operation of the display device such as the number of scan lines on one screen is appropriately controlled. Moreover, the CPU 1706 directly outputs image data and text / picture data to the image generating circuit 1707, and accesses an external computer or memory through the input / output interface circuit 1705 to access the image data and text / picture data. Enter.

In addition, the CPU 1706 may relate to tasks for other purposes. For example, it may directly relate to data generation functions and data processing functions such as personal computers or word processors. Alternatively, the CPU 1706 may be connected to an external computer network through the input / output interface circuit 1705 to perform tasks such as numerical calculations, for example, in cooperation with external equipment.

A user manipulates the input device 1714 to enter a program or data into the CPU 1706. The input device 1714 includes various input devices such as joysticks, bar code readers, and voice recognizers, as well as keyboards and mice. Can be used.

The decoder 1704 is a circuit which inversely converts various image signals input from the above-described image memory interface circuit 1707 into three primary color signals or luminance signals, that is, I and Q signals. The decoder 1704 preferably includes an image memory indicated by dashed lines in FIG. The picture memory is arranged to process TV signals, such as those of the MUSE system, which require picture memory for inverse conversion. Moreover, the image memory facilitates the display of still images. The image memory provides an advantage in cooperation with the image generating circuit 1707 and the CPU 1706 to facilitate image editing as well as image processing and editing such as omission, replenishment, expansion, contraction, and compositing of images.

The multiplexer 1703 appropriately selects an image to be displayed based on the control signal input from the CPU 1706. Specifically, the multiplexer 1703 selects a desired image signal from the inversely converted image signals input from the decoder 1704 and outputs the selected image signal to the driving circuit 1701. In this step, the multiplexer 1703 can select the image signal while switching the image signal within the display time for the scene so that the screen is divided into several regions so that different images are displayed in the same region as the so-called region on the multi-screen TV. have.

The display panel controller 1702 is a circuit that controls the operation of the driving circuit 1701 based on the control signal input from the CPU 1706 described above.

In relation to the basic operation of the display panel, for example, a signal for controlling the operation order of the driving power supply (not shown) for the display panel is output to the driving circuit 1701. In relation to the driving method of the display panel, for example, a signal for controlling the screen display frequency and the scanning mode (for example, interlaced or movie wall) is output to the driving circuit 1701. Furthermore, control signals related to adjustment of image quality such as brightness, color tone, contrast, etc. of an image to be displayed may be output to the driving circuit 1701.

The drive circuit 1701 is a circuit that generates a drive signal to be applied to the display panel 1700, and operates based on the image signal input from the multiplexer 1703 and the control signal from the display panel controller 1702 described above. do.

In addition to the circuit having the function described above, the image forming apparatus having the configuration shown in FIG. 18 can display image data from various image data sources on the display panel 1700. Specifically, various kinds of image signals such as TV broadcasts are inversely converted by the decoder, appropriately selected by the multiplexer 1703, and input to the driving circuit 1701. On the other hand, the display controller 1702 generates a control signal for controlling the operation of the driving circuit 1701 according to the image signal to be displayed. The driving circuit 1701 applies a driving signal to the display panel 1700 based on the above-described image signal and control signal. Thus, the display panel displays an image. These series of operations are collectively controlled by the CPU 1706.

The image-forming apparatus not only displays the selected data in the image memory built in the decoder 1704 and the data from the above-described image generating circuit 1707, but also can be displayed including the synthesis, erasure, concatenation, exchange and optimization of images. Expansion, reduction, rotation, movement, edge enhancement, omission, replenishment, color conversion, and aspect ratio conversion of images are also performed on image information. Furthermore, circuits for exclusive processing and editing of audio data can be arranged similarly to image data and image editing.

Accordingly, the image forming apparatus has collective functions such as display applications for TV broadcasting, terminal applications for TV conferences, image editing applications for processing still images and moving images, terminal applications for computers, business applications such as word processors, and game applications. It can have a wide range of applications for industrial and public welfare.

18 shows an example only when the image forming apparatus uses a display panel composed of an electron emitting device such as an electron beam source. However, the image forming apparatus according to the present invention is not limited only to that shown in FIG.

For example, among the components shown in FIG. 18, elements not related to the use purpose may be omitted. Conversely, additional elements may be used depending on the intended use. For example, when an image forming apparatus is used as a TV telephone, it is preferable to add a transmission circuit including a TV camera, a voice microphone, an illuminator and a modem.

An image forming apparatus using an electron emitting device such as an electron source can enable a thin display panel and reduce the depth of the image forming apparatus. In addition, a display panel using an electron emitting device such as an electron beam can have a large screen, high brightness and a large viewing angle, so that the image forming apparatus can display a high visibility and high quality image.

[Example 1]

An electron emission device having the configuration shown in FIGS. 1A and 1B was manufactured as Example 1 of the present invention. Example 1 will be described with reference to FIGS. 1A and 1B and 2A to 2D. Silica glass was used as the substrate 11 and Pt was used as the material of the device electrode in consideration of stability against humidity and oxidation. Further, the thickness of the conductive film 14 was set to 30 nm in consideration of the resistance value between the device electrodes 12 and 13. In Example 1, L was 20 µm, W was 100 µm, and the film thickness d was 10 nm.

The substrate on which the electrodes 12 and 13 were disposed was coated with an organic Pd solution ("ccp-4230 by Okuno Chemical Co., Ltd.) to form an electrically conductive film 14 to form an organometallic film. Heated, and the film was patterned (FIGS. 2A and 2B).

Then, a triangular wave pulse having a constant pulse height shown in FIG. 3 was repeatedly applied. The pulse width T1 and the pulse interval T2 shown in FIG. 3 were set to 10 μsec and 1 msec, respectively, and the amplitude of the triangular wave was set to 10V. In this state, the second gap 16 was formed by applying a pulse voltage for 600 seconds. (FIG. 2C).

Then, the above-described device was activated. Specifically, the substrate on which the device was formed was placed in the device shown in Fig. 4, and acetone was introduced as an organic material gas into a vacuum space that was sufficiently evacuated using an ion pump or the like to maintain 1 × 10 −5 Pa. A voltage was applied to the electrodes 12, 13 using the same triangle wave pulses used to form the second gap, and the electron beam was irradiated at an acceleration voltage of 20 kV. However, the pulse width, pulse interval, and pulse height of the triangular wave pulses were set to 1 msec, 10 msec, and 15V, respectively.

The activation process, that is, the step of forming the carbon film 15 was performed until the selected current If. The transmission electron microcopy of the obtained device showed a film thickness of 50 nm in the vicinity of the gap 17. Further, the carbon film 15 opposes the first gap sandwiched in the middle as shown in FIG. 2D. Furthermore, the first gap 17 was narrower than the second gap 16 and disposed in the second gap 16. Raman spectroscopy also showed that the carbon film 15 had a graphite structure and had high crystallinity.

Furthermore, when observed through an atomic force / tunnel microscope with an atomic force microscope probe made to measure the electrical conductivity distribution of the sample in contact with the probe, no regions of high resistance exist in the carbon film 15. It turned out that In addition, the probe was kept in contact with the electrically conductive film 145 during the measurement. The value of the resistivity in the width direction of the film was not greater than 0.001 mm. As a result of comparing this value with the carbon film 15 formed without electron irradiation, there was a variation over one place.

The above-described device substrate was placed in the measuring device shown in Fig. 5, and its electron emission efficiency was measured by applying a voltage of 1 kV to the anode with the distance H between the anode and the electron emitting device being set to 2 mm.

First, the organic material gas was evacuated from the vacuum vessel 55 to prevent new deposition of carbon or carbon composite material. A sorption pump was used as the vacuum device 56 to evacuate the vacuum vessel 55 without using oil so that oil flowing out of the device does not affect the device characteristics. The partial pressure of the organic component in the vacuum vessel 55 was adjusted to 1 x 10 &lt; -8 &gt; Pa, in which carbon or carbon compound was hardly deposited. In this step, the vacuum vessel was heated to a temperature no lower than 200 ° C. to exhaust the molecules of the organic material absorbed by the inner wall of the vacuum vessel and the electron emitting device.

As a result, a relationship between the device current If and the discharge current Ie as shown in Fig. 6 was obtained. Further, the electron emission efficiency η was defined as the ratio of Ie to If when Vf and Va were fixed at 15V and 1kV, respectively, and the variation in η over time was measured while the electrons were emitted.

As a result, initial electron emission efficiency improved by 0.05% or more. In addition, the fluctuation of η over time was significantly suppressed compared to the electron emitting device manufactured by the prior art. In the conventional device, when the initial η is 0.1%, the improvement of η is improved at a rate of 0.01% / 1000h (h is time), whereas the electron emission device manufactured according to the method of the present invention has a rate of change of η less than 1/5. Suppressed.

(Example 2)

As Example 2 of the present invention, an electron source having the configuration shown in FIGS. 7A and 7B was produced through the activation step shown in FIGS. 9A and 9B.

In Example 2, the basic construction, material, and method were the same as in Example 1, but the film thicknesses of L1, W, and the electrodes were set to 5 µm, 100 µm, and 10 nm, respectively. In addition, the width L2 of the common device electrode was set to 5 µm.

Prior to the formation of the electron emission region, an electron emission device was formed through a step similar to that shown in Example 1. Then, the activation process was performed by applying the pulse voltages shown in FIGS. 8A and 8B to both ends of the device electrodes 73 and 74 with the common electrode grounded. In example 2, acetone was introduced as organic material and maintained at 1 × 10 −5 Pa. Pulse width T1, pulse voltage and pulse interval t2 were set to 1 msec, 15 V, and 200 msec, respectively. Formation of the electrically conductive films 76 and 78 continued until the device current If reached a predetermined level.

The transmission electron microcopy of the device thus obtained showed that the carbon film had a thickness of 50 nm in the vicinity of the first gap 17 forming the electron emission region. Observations by transmission microcopy and Raman spectrocopy of the electron-emitting device thus obtained showed that the carbon films 76 and 78 have a graphite structure and a high crystal structure.

In addition, when observed under an atomic force / tunnel microscope with a probe made to be electrically conductive as in Example 1 so that the microscope could measure the electrical conductivity distribution of the sample, high resistance was observed in the carbon films 76 and 78. It was found that no area was present. In addition, the specific resistance value in the width direction did not exceed 0.0001 mm. Compared with the measured value when the carbon film was formed without electron irradiation, this value showed variation over two places.

An electron emitting device formed by the above-described method was placed in the measuring device shown in FIG. 5 and its electron emission efficiency was measured. However, driving was only on the electron emission region. The common device electrode was set to a high potential so that electrons are always emitted towards the common device electrode. The electron emission efficiency η was defined as the ratio of Ie to If, and the variation in η over time with Vf and Va fixed at 15 V and 1 kV, respectively, was measured.

As a result, the initial electron emission efficiency improved by 0.1% or more. Furthermore, the electron emitting device significantly suppressed the variation with time of η compared to the electron emitting device manufactured by the conventional method. When the initial η is 0.1%, the conventional device shows improvement of η at a rate of 0.01% / 1000h (h is time), whereas the electron emission device manufactured according to the method of the present invention has a variation rate η less than 1/10. Suppressed.

(Example 3)

In Example 3, an electron emitting device having the configuration shown in Figs. 21A and 21B was manufactured. Example 3 will be described with reference to FIGS. 21A, 21B, 22A, 22B, and 23. A crystal was used as the substrate 11 and Pt was used as a material for the device electrodes 12 and 13 in consideration of stability against moisture and oxidation.

The activation process was then performed on the device.

Specifically, the substrate on which the device electrodes 12 and 13 are formed was placed in the device shown in Fig. 23, and acetone as an organic material gas at a vacuum speed sufficiently vacuumed by a vacuum pump or the like and maintained at 1 × 10 −5 Pa. This was introduced, and the pulse shown in FIG. 8A was applied to the electrodes 12 and 13. T1 and T2 shown in FIG. 8A were set to 1 msec and 10 msec, respectively. At the same time, the substrate was irradiated with an electron beam with an acceleration voltage set to 2 kV.

The step of forming the carbon film 15 was performed until the device current If reached a predetermined level. As a result of observation by the transmission electron microcopy of the device thus obtained, a first gap 17 as shown in Figs. 21a and 21b was formed between the device electrodes 12 and 13, and the electrodes 12 and 13 were formed. The carbon film 15 was continuously formed over. The gap 17 was located near the middle between the electrodes 12 and 13. Furthermore, as a result of observation by Raman spectroscopy, the carbon film 15 had a graphite layer structure and a high crystal structure.

The electron emitting device was placed in the measuring device shown in Fig. 5, and the electron emission efficiency was measured while maintaining the anode voltage at 1 kV and setting the distance H between the anode and the electron emitting device to 2 mm.

First, organic material was evacuated from the vacuum vessel to prevent new deposition of carbon or carbon composites. In order that the characteristics of the apparatus are not affected by the oil flowing out of the apparatus, an oil-free sorption pump was used as the vacuum apparatus 66 for evacuating the vacuum vessel 65. The partial pressure of the organic compound in the vacuum vessel 65 was adjusted to a level where no carbon or carbon compound was newly deposited. In this step, the vacuum vessel was heated to 200 ° C. or higher to facilitate the evacuation of molecules of the organic material absorbed by the inner wall of the vacuum vessel or the electron emitting device.

As a result, the relationship between the device current If and the discharge current Ie shown in FIG. 6 was obtained. When the initial values are defined as If, Ie, and η, and the ratio of Ie to If is defined as the electron emission efficiency η, the initial value according to time while the electrons are emitted with Vf and Va fixed at 15 V and 1 kV, respectively. The variation of was measured.

(Example 4)

In Example 4, the image forming apparatus 138 shown in Fig. 13 was manufactured in accordance with the method described in Example 3. In addition, the substrate 121 also serves as the back plate 131.

First, 500 pairs of device electrodes 12 and 13 and 100 pairs of device electrodes 12 and 13 were formed on the glass substrate 121 in the X direction and the Y direction by the offset printing technique, respectively (FIG. 24A). Subsequently, 500 wires 122 to be connected to the electrode 121 were formed in the X direction by the screen printing method (FIG. 24B) 100 insulating layers 124 were substantially perpendicular to the X direction by the screen printing method. (FIG. 24C) 1000 wires were formed on the insulating layer 124 in the Y direction and connected to the electrode 13 (FIG. 25D), as in Example 3, between the device electrodes 12 and 13; The carbon film 15 was formed as shown in Fig. 23 by applying a voltage across the device electrodes 12 and 13 while irradiating the portion with an electron beam such as a DC voltage from the electron emitting means 51. Fig. 25E. And 23) an electron source was formed through the above-described process.

Subsequently, an electron source was placed on the front plate 136 in which the fluorescent material as the image forming member as shown in FIG. 14A was disposed. An outer frame 132 with a preliminary placement coupling member was placed between the electron source and the faceplate to seal by heating and pressing the frame under vacuum.

The image forming apparatus 138 was manufactured through the above-described process.

When the image forming apparatus was driven by being connected to the driving circuit shown in Fig. 15, it was possible to display an image having a stable and high luminance for a long time.

(Example 5)

In Example 5, the image forming apparatus 138 shown in Fig. 13 was manufactured in accordance with the method of Example 1. In addition, in Example 5, the substrate 121 also serves as the back plate 131.

First, 500 pairs of device electrodes 12 and 13 and 1000 pairs of device electrodes 12 and 13 were formed on the glass substrate 121 in the X and Y directions, respectively, by an offset printing method (FIG. 24A). Thus, 500 wires 122 to be connected to the electrode 122 were formed in the X direction by the screen printing method. (FIG. 24B) 1000 insulating layers 124 were substantially perpendicular to the X direction by the screen printing method. It formed in one direction (FIG. 24C). 1000 wires 123 were formed in the Y direction on the insulating layer 124, and were connected to the electrode 13. (FIG. 26D). An electrically conductive film 14 was formed between the device electrodes 12 and 13 by the inkjet method. (FIG. 26E) As in Example 1, in the forming step, a voltage was applied to the device electrodes 12 and 13 to form a device electrode ( A gap 16 was formed in the portion between 12 and 13 (FIG. 26F). The portion of the device electrode (Fig. 26F) was irradiated with an electron beam such as a DC voltage from the electron emission means 51 to the portion between the device electrodes 12 and 13. 12 and 13 were applied to form a carbon film 150 as shown in Figs. 2A to 2D and Fig. 4. An electron beam source was produced through the above-described process.

Subsequently, the electron beam was placed on the front plate 136 in which the fluorescent material as the image forming member is disposed, as shown in FIG. 14A, with an outer frame 132 having a preliminary arrangement between the electron source and the front plate. Placed and sealed by heating and pressing the frame under vacuum.

The image forming apparatus 138 was manufactured in accordance with the above-described procedure.

When the image forming apparatus is driven in connection with the driving circuit shown in Fig. 15, the apparatus can display a uniform, high brightness uniform image for a long time.

The manufacturing method of the electron emitting device manufactured according to the present invention can form a carbon film having a low resistance and high uniformity, which can be formed while the method of the present invention irradiates a carbon film having carbon as a main component with sufficient electrons. Because it allows. Therefore, the manufacturing method according to the present invention improves the initial electron emission efficiency and limits the change in the physical properties of the carbon film even when irradiating the carbon film with electrons emitted from the electron emission region during driving, thereby preventing the variation in the electron emission efficiency. Makes it possible to manufacture electron emitting devices.

Therefore, the present invention makes it possible to provide an electron source which is stable, uniform and has high electron emission efficiency, and to manufacture a high brightness and reliable image forming apparatus using the electron source.

Claims (16)

In the electron emitting device manufacturing method, Disposing a conductive member having a second gap on the substrate; Irradiating at least said second gap with an electron beam from an electron emitting means disposed away from said conductive member in an atmosphere comprising a carbon compound; And Applying a voltage to the conductive member in an atmosphere containing the carbon compound Method of manufacturing an electron emission device comprising a. In the electron emitting device manufacturing method, Disposing a first and a second conductive member having a second gap thereon on the substrate; Irradiating at least said second gap with an electron beam from an electron emitting means disposed away from said conductive member in an atmosphere comprising a carbon compound; And Applying a voltage across both the first and second conductive members in an atmosphere containing the carbon compound Method of manufacturing an electron emission device comprising a. In the manufacturing method of an electron emitting device, Disposing a conductive member having a second gap on the substrate; Irradiating at least the second gap with an electron beam from an electron emitting means disposed away from the conductive member in an atmosphere containing a carbon compound while applying a voltage to the conductive member Method of manufacturing an electron emission device comprising a. In the manufacturing method of an electron emitting device, Disposing a first and a second conductive member having a second gap thereon on the substrate; Irradiating at least said second gap with an electron beam from an electron emitting means disposed away from said conductive member in an atmosphere containing a carbon compound while applying voltage to said first and second conductive members Method of manufacturing an electron emission device comprising a. In the manufacturing method of an electron emitting device, Disposing a conductive member having a second gap on the substrate; Irradiating at least the second gap with an electron beam from an electron emitting means disposed away from the conductive member in an atmosphere containing a carbon compound in a period in which a voltage is applied to the conductive member Method of manufacturing an electron emission device comprising a. In the manufacturing method of an electron emitting device, Disposing a first and a second conductive member having a second gap thereon on the substrate; Irradiating at least the second gap with an electron beam from an electron emitting means disposed away from the conductive member in an atmosphere containing a carbon compound in a period in which a voltage is applied across the first and second conductive members. Method of manufacturing an electron emission device comprising a. 6. The electron emission of claim 1, 3 or 5, wherein the conductive member having the second gap is a conductive film connecting a pair of electrodes to each other and having the second gap in a part thereof. Device manufacturing method. The method of manufacturing the electron emission device according to claim 2, 4 or 6, wherein the conductive member is a pair of electrodes disposed with the second gap interposed therebetween. The said conductive member is a 1st conductive film and a 2nd conductive film which are connected to the 1st and 2nd electrode arrange | positioned separately, respectively, and the said 2nd gap is interposed. A method of manufacturing an electron emitting device. 7. A method according to any one of claims 1 to 6, wherein said applied voltage is a pulsed voltage. 7. A method according to any one of the preceding claims, wherein the electron beam has an energy level of greater than 1 keV and less than 20 keV. In the manufacturing method of the electron source which has a some electron emission device, The method of manufacturing an electron source, wherein the electron emission device is manufactured by the manufacturing method according to any one of claims 1 to 6. A manufacturing method of an image forming apparatus having an electron source and an image forming member, wherein the electron source is manufactured by the manufacturing method according to claim 12. An electron emission device having a carbon film, wherein the carbon film has a specific resistance of 0.001 dBm or less. An electron source having a plurality of electron emission devices, wherein the electron emission device is the electron emission device according to claim 14. An image forming apparatus having an electron source and an image forming member, wherein the electron source is the electron source according to claim 15.